This invention relates generally, as indicated, to a landing gear mechanism including a bypass valve assembly for substantially reducing or eliminting high damping loads as the landing gear mechanism negotiates bumps during taxiing. Such a landing gear mechanism is especially designed for high performance aircraft, to permit such aircraft to operate on relatively rough runways.
Typically, landing gears for high performance aircraft such as operated by the military are not designed to operate on rough runways made rough, for example, as a result of temporary repairs to bomb damaged areas and the like.
It is possible to make a landing gear that is effective at heavy take-off weight and still provide the required shock strut stroke during landing to absorb the required amount of landing energy to prevent damage to the landing gear during landing on rough runways by providing the landing gear with different low spring rate load ranges as described in applicant's own U.S. Pat. No. 4,552,324, dated Nov. 12, 1985, the disclosure of which is incorporated herein by refernce.
The landing gear of such patent can also be made to discriminate between shock strut extension during normal ground roll and extension as the strut tire follows a sudden recess during forward travel, preventing cavitation in the lower piston chamber of the landing gear as the landing gear extends, and providing for piston rebound damping as the piston approaches the end of its stroke during full extension.
In addition, provision can be made in the landing gear of such patent for substantially reducing or eliminating high damping loads as the landing gear negotiate bumps. Briefly, this is accomplished by the opening of a taxi instroke bypass valve as soon as the landing energy stroke is complete to allow fluid to pass more freely from the lower piston chamber to the upper piston chamber, bypassing the primary flow orifice.
The landing gear mechanism of the present invention may include one or more of the various features disclosed in such patent. However, the present landing gear mechanism includes a novel bypass valve assembly for reducing or substantially eliminating the high damping loads that might otherwise take place during taxiing as the landing gear negotiates bumps which is better suited to being packaged into a smaller space than the corresponding mechanism of such patent.